The invention relates to an amplifier circuit with a basic transistor and a load transistor.
Such an amplifier circuit comprises at least one basic transistor, at least one load transistor, and at least one impedance element. The basic transistor is connected to the impedance element and the load transistor. Further, the amplifier circuit comprises an amplifier input and an amplifier output, with the amplifier input being connected to the gate contact to the basic transistor and the amplifier output being connected to a contact of the impedance element.
In many technical applications it is necessary to achieve high energy efficiencies for power amplifiers in the microwave frequency range. Typically this range of applications demands a square wave-input voltage for optimal efficiency.
Passive harmonic matching amplifiers as well as active driver amplifier circuits are know from prior art.
In the amplifier circuits according to prior art it is disadvantageous that passive harmonic matching amplifiers operate only in a narrow frequency band and active driver amplification circuits can only be used in a low power range.
Switch-mode power amplifiers are also known from prior art. They show an inverter driver stage and a power transistor. When GaN-semiconductor transistors or transistors of the group of the III-V-semiconductors of prior art are used, these transistors are typically formed as non-complementary transistors.
Inverter driver stages are typically realized via complementary Si-based semiconductor technology, while power transistors are typically realized via non-complementary GaN-based semiconductor technology. Here it is disadvantageous that these two semiconductor technologies cannot be realized on a single chip. It is therefore necessary to connect the driver stage and the power transistor stage via bond-wire technology. This leads to power loss, parasitic effects, and distortions of the square wave. Previous approaches known from prior art suggest the use of integrated CMOS-inverters on a Si-basis. These amplifier circuits are however optimized for the operation at voltages ranging at one Volt, while the GaN-based power transistors require a voltage ranging at 5 V.
In these concepts of prior art it is further disadvantageous that the scaling towards higher output power requires a large area on the chip and thus it is costly.